A study released on December 10 sends out a strongly worded warning about risks of kidney, liver, and other organ damage from the most popular weight drugs on the market. A University of Rhode Island study funded by the National Institutes of Health (NIH) states that orlistat, which goes by the prescription brand name Xenical and the over-the-counter name Alli, can cause “severe toxicity” to major internal organs.

The Food and Drug Administration on Monday warned consumers about a counterfeit version of GlaxoSmithKline’s weight-loss drug Alli. Alli is sold over-the-counter in a variety of retail stores. The counterfeit version was purchased by consumers on the Internet, and GlaxoSmithKline started receiving complaints about the product last month. Glaxo said the product was purchased from online auction sites like eBay.